Method for controlling the growth of plants

ABSTRACT

A method for controlling the growth of plants, characterized by applying a plant growth regulator containing as active ingredient a benzenesulfonamide derivative represented by the general formula, ##STR1## wherein X is a halogen atom, an alkyl group having 1 to 5 carbon atoms, a nitro group, an amino group, an alkoxy group having 1 to 5 carbon atoms, an alkylthio group having 1 to 5 carbon atoms, an alkylsulfonyl group having 1 to 5 carbon atoms, or a group of the formula R 3  CONH-- (where R 3  is an alkyl group having 1 to 5 carbon atoms); n is an integer of 0 to 5; R 1  is hydrogen, an alkyl group having 1 to 5 carbon atoms, a phenyl group, a group of the formula --(A)--COOR 4  [where R 4  is hydrogen, an alkyl group having 1 to 5 carbon atoms, a cation such as Na + , K + , ammonium or a quaternary ammonium ion, and (A) is a group of the formula --(CH 2 ) m  -- (where m is an integer of 1 to 3), or a group of the formula ##STR2## (where R 5  and R 6  are individually hydrogen or an alkyl group having 1 to 5 carbon atoms)]; and R 2  is a straight chain, branched chain or alicyclic alkyl group having 1 to 15 carbon atoms, a hydroxyalkyl group having 1 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms, a hydroxyl group, an aminoalkyl group having 1 to 5 carbon atoms, a cyano-C 1-5  -alkyl, an alkenyl group having 2 to 5 carbon atoms, a C 1-5  -alkoxy-C 1-5  alkyl group, a sulfoalkyl group having 1 to 5 carbon atoms, a phenyl-substituted alkyl group having 1 to 5 carbon atoms, or a group of the formula --(A)--COOR 4  (where R 4  and (A) are as defined above), when R 1  is hydrogen; is a hydroxyalkyl group having 1 to 5 carbon atoms, a group of the formula --(A)--COOR 4  (where R 4  and (A) are as defined above), a group of the formula --(B)--OOCR 7  [where R 7  is a phenyl group or an alkyl group having 1 to 5 carbon atoms, and (B) is a group of the formula (CH 2 ) j  -- (where j is an integer of 1 to 3), or a group of the formula ##STR3## (where R 5  and R 6  are as defined above)], when R 1  is an alkyl group having 1 to 5 carbon atoms; and is a group of the formula --(A)--COOR 4  (where R 4  and (A) are as defined above), when R 1  is a phenyl group or a group of the formula --(A)--COOR 4  (where R 4  and (A) are as defined above).

This invention relates to a method for controlling the growth of plants.More particularly, the invention is concerned with controlling thegrowth of plants by using a plant growth regulator containing as activeingredient a benzenesulfonamide derivative represented by the generalformula, ##STR4## wherein X may be the same or different and is ahalogen atom, an alkyl group having 1 to 5 carbon atoms, a nitro group,an amino group, an alkoxy group having 1 to 5 carbon atoms, an alkylthiogroup having 1 to 5 carbon atoms, an alkylsulfonyl group having 1 to 5carbon atoms, or a group of the formula R₃ CONH--(where R₃ is an alkylgroup having 1 to 5 carbon atoms); n is an integer of 0 to 5; R₁ ishydrogen, an alkyl group having 1 to 5 carbon atoms, a phenyl group, agroup of the formula --(A)--COOR₄ [where R₄ is hydrogen, an alkyl grouphaving 1 to 5 carbon atoms, a cation such as Na⁺, K⁺ or NH₄ ⁺ or aquaternary ammonium ion, and (A) is a group of the formula --(CH₂).sub.m -- (where m is an integer of 1 to 3), or a group of the formula##STR5## (where R₅ and R₆ are each individually hydrogen or an alkylgroup having 1 to 5 carbon atoms)]; and R₂ is a straight chain, branchedchain or alicyclic alkyl group having 1 to 15 carbon atoms, ahydroxyalkyl group having 1 to 5 carbon atoms, haloalkyl group having 1to 5 carbon atoms, a hydroxyl group, an aminoalkyl group having 1 to 5carbon atoms, a cyano-C₁₋₅ -alkyl group, an alkenyl group having 2 to 5carbon atoms, a C₁₋₅ -alkoxy-C₁₋₅ -alkyl group, a sulfoalkyl grouphaving 1 to 5 carbon atoms, a phenylsubstituted alkyl group having 1 to5 carbon atoms, or a group of the formula --(A)--COOR₄ [wherein R₄ and(A) are as defined above], when R₁ is hydrogen; is a hydroxyalkyl grouphaving 1 to 5 carbon atoms, a group of the formula --(A)--COOR₄ whereinR₄ and (A) are as defined above, a group of the formula --(B)--OOCR₇[where R₇ is a phenyl group or a alkyl group having 1 to 5 carbon atoms,and (B) is a group of the formula (CH₂)_(j) -- (where j is an integer of1 to 3) or a group of the formula ##STR6## wherein R₅ and R₆ are asdefined above], when R₁ is an alkyl group having 1 to 5 carbon atoms;and is a group of the formula --(A)--COOR₄, wherein R₄ and (A) are asdefined above, when R₁ is a phenyl group or a group of the formula--(A)--COOR₄ wherein R₄ and (A) are as defined above.

In the cultivation of plants, the effort of controlling the growth ofplants to the direction desired by human was relied over a long periodof time on the improvement in variety of plants or on the technique offertilization. As the mechanism of growth control of plants with planthormones has been clarified in recent years, attempts of direct plantgrowth control using chemical substances have come to be carried outpositively. As the result, there is seen such a trend that chemicalsutilized actually in agriculture and horticulture are increasing innumber, e.g. the utilization of α-naphthaleneacetic acid for promotionof root-taking of planted cuttings, the utilization of gibberellin formaking grapes seedless, and the utilization ofN-dimethylamino-succinamic acid for dwarfing of chrysanthemums. However,the fields, in which plant growth regulators have been put intopractical use, are far smaller in number than the fields, in which theapplication of said regulators is expected. Further, even the chemicals,which have already been developed, have many such problems that theyvary in effectiveness or cause phytotoxicity depending on theconcentrations and the time of application thereof. Moreover, theconventional plant growth regulators vary in effectiveness, in general,depending on the kind of plant to be treated, and it is a frequentlyexperienced fact that chemicals which have effects on broad-leaved cropsare entirely ineffective for grass crops, or chemicals which haveeffects on wheat have no effect on rice.

With an aim to freely control the growth of various plants withchemicals, the present inventors conducted extensive studies for yearsto find that benzenesulfonamide derivatives have prominent plantgrowth-regulating actions. Based on this finding, the inventors haveaccomplished the present invention.

The compounds used in the present invention have such physiologicalcharacteristics that they are stronger in plant growth-controllingaction than in plant growth-promoting action, and are useful in thecases where plants are required to be controlled in growth.

It is an object of this invention to provide a method for controllingthe growth of plants. It is another object of this invention to provideplant growth regulating compositions. It is still another object of thisinvention to provide a method for effectively regulating the growth ofcultivated plants both in stem-leaf treatment and in soil treatmentwithout any phytotoxicity. Other objects and advantages of thisinvention will be apparent from the following description.

According to this invention, there is provided a method for controllingthe growth of cultivated plants by applying a plant growth regulatorcontaining as active ingredient at least one benzenesulfonamidederivative represented by the general formula. ##STR7## wherein X, R₁,R₂ and n are the same as defined above. Preferred examples of thebenzenesulfonamide derivative are the compounds wherein X can be thesame or different and is a halogen atom, methyl group or methoxy group;n is an integer of 0 to 3; R₁ is hydrogen, methyl group, ethyl group or--CH₂ --COOH; R₂ is hydroxyethyl group (--CH₂ --CH₂ --OH), hydroxypropylgroup (--CH₂ --CH₂ --CH₂ --OH), hydroxybutyl group, --CH₂ --COOH, --CH₂--CH₂ --COOH, --CH(CH₃)--COOH, --CH₂ --CH₂ --CH₂ --COOH, --C(CH₃)₂--COOH, --CH₂ --COOCH₃, --CH₂ --CH₂ --COOCH₃, --CH(CH₃)--COOCH₃, when R₁is hydrogen, is hydroxyethyl group, --CH₂ --COOH, --CH₂ -COOCH₃, --CH₂--CH₂ --OOC.CH₃ or ##STR8## When R₁ is methyl or ethyl group, and is--CH₂ --COOH, when R₁ is --CH₂ --COOH. Representative benzenesulfonamidederivative which can be used in the present invention are set forthbelow.

    __________________________________________________________________________    1)                                                                                ##STR9##             wherein R is hydrogen, methyl or ethyl               2)                                                                                ##STR10##            wherein R is hydrogen, methyl or CH.sub.2 COOH                                wherein R is CH.sub.2 CH.sub.2 COOH,                 3)                                                                                ##STR11##                                                                                           ##STR12##                                           4)                                                                                ##STR13##            wherein R is methyl or  phenyl                       5)                                                                                ##STR14##            wherein X is methyl or a halogen atom                6)                                                                                ##STR15##            wherein X is methoxy, chlorine or fluorine atom      7)                                                                                ##STR16##            wherein R is CH.sub.2CH.sub.2 OH, CH.sub.2CH.sub.                             2CH.sub.2 OH, CH.sub.2CH.sub.2CH.sub.2CH.sub.2OH                              or C(CH.sub.3).sub.2CH.sub.2OH                       8)                                                                                ##STR17##            wherein R is hydrogen or methyl                      9)                                                                                ##STR18##            wherein X is methyl, methoxy or chlorine and R                                is CH.sub.2 COOH,                                                              ##STR19##                                           10)                                                                               ##STR20##                                                                                           ##STR21##                                                                    CH.sub.2 CH.sub.2 COOCH.sub.3, CH.sub.2 CH.sub.2                              CH.sub.2 COOCH.sub.3                                                           ##STR22##                                           11)                                                                               ##STR23##                                                                 12)                                                                               ##STR24##            wherein R is CH.sub.2CH.sub.2CH.sub.2 COOH or                                 C(CH.sub.3).sub.2COOH                                13)                                                                               ##STR25##                                                                 14)                                                                               ##STR26##            wherein R is hydrogen or methyl                      15)                                                                               ##STR27##            wherein X is methyl or chlorine and R is methyl                               or phenyl                                            16)                                                                               ##STR28##            wherein X is methyl, methoxy or chlorine atom        17)                                                                               ##STR29##                                                                 18)                                                                               ##STR30##                                                                 19)                                                                               ##STR31##                                                                 20)                                                                               ##STR32##                                                                 21)                                                                               ##STR33##                                                                 22)                                                                               ##STR34##                                                                 23)                                                                               ##STR35##                                                                 __________________________________________________________________________

Heretofore, the aforesaid N-dimethylamino-succinamic acid has chieflybeen used as a plant growth regulator for Pot-mum cultivation. However,it is well know that when sprayed to stems and leaves of plants, theN-dimethylamino-succinamic acid is effective, but when used in soiltreatment, it is too weak in effectiveness to be used in practice. Incontrast, the compounds used in the present invention show prominentgrowth retarding actions both in stem-leaf treatment and in soiltreatment, and hence may be said to be extremely useful plant growthregulators.

Further, the lodging of paddy rice plants and wheat plants due totyphoons and heavy rains, which are frequently encountered at the lattergrowth stage of said plants, lowers the ripening degree of cereal grainsto invite great decrease in yield or makes the mechanical reaping of theplants difficult, and thus is a serious problem in the cultivation ofsaid plants. While extensive studies have been made to make rice andwheat plants shorter in height by use of growth regulators so as toincrease the plants in resistance to lodging, compounds which caneffectively be put into practical use have not been found yet.

The compounds used in the present invention not only have actions ofcontrolling the elongation of rice and wheat plants but also have sucheffects as to promote the increase in number of tillers and ears of theplants to increase the yields of rice and wheat crops. Further, theyhave actions of inhibiting the elongation of succulent shoot of fruittrees and turfs, and of regulating the vegetative growth of fruit treesto properly control the trees in flowering time and fruit-ripening time.Thus, the compounds of the present invention can be utilized in variousfields.

Typical examples of the compounds used in the present invention andphysical properties thereof are shown in Table 1 below, but compoundsusable in the present invention are not limited thereto.

                                      Table 1                                     __________________________________________________________________________     ##STR36##                                                                    Compound                                                                      No.   X.sub.n n R.sub.1                                                                            R.sub.2     Physical properties                          __________________________________________________________________________    (1)   4-CH.sub.3                                                                              H    C.sub.4 H.sub.9 (n)                                                                       m.p. 36-38° C                         (2)   "       " "    C.sub.4 H.sub.9 (sec)                                                                     m.p. 54-55° C                         (3)   4-Cl    " "    C.sub.4 H.sub.9 (n)                                                                       m.p. 41.5-42.5° C                     (4)   "       " "    C.sub.4 H.sub.9 (iso)                                                                     m.p. 98.5-8.5° C                      (5)   "       " "    C.sub.4 H.sub.9 (sec)                                                                     m.p. 57-58.5° C                       (6)   "       " "    C.sub.4 H.sub.9 (tert)                                                                    m.p. 121.5-122.5° C                   (7)   "       " "    C.sub.5 H.sub.13 (n)                                                                      m.p. 41-42.5° C                       (8)   4-CH.sub.3                                                                            " "                                                                                   ##STR37##  m.p. 83-83.5° C                       (9)   2,4,6-tri-Cl                                                                          3 "    C.sub.4 H.sub.9 (sec)                                                                     m.p. 106-107.5° C                     (10)  "       3 "    C.sub.12 H.sub.25 (n)                                                                     m.p. 55.5-56° C                       (11)  4-CH.sub.3                                                                            1 "                                                                                   ##STR38##  m.p. 112-113.5° C                     (12)  "       " "    CH.sub.2 . CHCH.sub.2                                                                     m.p. 60.5-61.5° C                     (13)  4-CH.sub.3                                                                            " "    CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5                                                        m.p. 35.5-36.5° C                     (14)  "       " "    CH.sub.2 CN m.p. 134.sub.]135.5° C                (15)  "       " "    CH.sub.2 CH.sub.2 NH.sub.2                                                                m.p. 123-126° C                       (16)  4-CL    " "    CH.sub.2 CH.sub.2 CN                                                                      m.p. 84-86° C                         (17)  4-CH.sub.3                                                                            " "    CH.sub.2 CH.sub.2 CL                                                                      m.p. 96.5-98° C                       (18)  "       " "    OH          m.p. 135-137.5° C                     (19)  4-Cl    " "    "           m.p. 109-111° C                       (20)  --      0 "    CH.sub.2 CH.sub.2 OH                                                                      b.p. 194-197° C/2.5 mmHg              (21)  4-CH.sub.3                                                                            " "    b.p. 195° C/0.6 mmHg                                                               m.p. 50-51.5° C                       (22)  4-F     " "    "           m.p. 68-70° C                         (23)  4-Cl    " `    "           m.p. 96.5-98° C                       (24)  4:Br    " "    "           m.p. 82.5-85° C                       (25)  4-I     " "    "           m.p. 87-89° C                         (26)  2,4-di-Cl                                                                             2 "    "           m.p. 68.5-71.5° C                     (27)  2-CH.sub.3 4-Cl                                                                       2 "    "           m.p. 88-91° C                         (28)  2-CH.sub.3 -5-Cl                                                                      2 "    "           m.p. 107-111° C                       (29)  2,4-di-CH.sub.3                                                                       2 "    "           m.p. 70-72° C                         (30)  2,4,6-tri-Cl                                                                          3 "    "           m.p. 128.5-130° C                     (31)  4:NO.sub.2                                                                            1 "    "           m.p. 113-116° C                       (32)  4-CH.sub.3 CONH                                                                       1 "    "           m.p. 121-123° C                       (33)  4-CH.sub.3 S                                                                          " "    "           m.p. 84-85.5° C                       (34)  4-CH.sub.3 SO.sub.2                                                                   " "    "           m.p. 118.5-122.5° C                   (35)  4-CH.sub.3 O                                                                          " "    "           n.sub.D.sup.30 : 1.5535                      (36)  ,4,6-tri-CHhd 3                                                                       3 "    "           m.p. 74.5-76.5° C                     (37)  4-CH.sub.3                                                                            1 "    CH.sub.2 CH.sub.2 CH.sub.2 OH                                                             b.p. 204-208° C/1 mmHg                                                 m.p. 49-51° C                         (38)  "       " "    CH.sub.2 CH(OH)CH.sub.3                                                                   b.p. 179-184° C/0.35 mmHg             (39)  2,4,6-tri-Cl                                                                          3 "    CHhd 2 CH.sub.2 CH.sub.2 OH                                                               m.p. 104.5-106.5° C                   (40)  2,4,6-tri-Cl                                                                          " "    C(CH.sub.3).sub.2 CH.sub.2 OH                                                             m.p. 128.5-130° C                     (41)  2,4,6-tri-CH.sub.3                                                                    " "    "           m.p. 93.5-95.5° C                     (42)  4-Cl    1 "    "           m.p. 11.5-114° C                      (43)  4-NH.sub.2                                                                            " "    C.sub.4 H.sub.9 (sec)                                                                     m.p. 132.5-133.5° C                   (44)  4-Cl    " "    CH.sub.2 CH.sub.2 SO.sub.3 H                                                              m.p. 149-150° C                       (45)  --      0 CH.sub. 3                                                                          CH.sub.2 CH.sub.2 OH                                                                      b.p. 168-169° C/0.2 mmHg              (46)  4-CH.sub.3                                                                            1 "    "           b.p. 184-186° C/0.65 mmHg             (47)  4-Cl    " `    "           b.p. 180° C/0.5 mmHg                  (48)  4-      " "    "           b.p. 146-147.5° C/0.45 mmHg                                            m.p.60-61.5° C                        (49)  4-CH.sub.3 O                                                                          " "    "           b.p. 198.5-200° C/0.85 mmHg                                            m.p. 73.5-75.5° C                     (50)  4-NO.sub.2                                                                            " "    "           m.p. 82.5-85° C                       (51)  -       0 C.sub.2 H.sub.5                                                                    "           m.p. 152-153.5° C/0.5 mmHg            52)   2-CH.sub.3 -5-Cl                                                                      2 CH.sub.3                                                                           "           b.p. 161-162° C/0.28 mmHg             (53)  2,4-di-CH.sub.3                                                                       " "    "           b.p. 164-165° C/0.5d mmHg             (54)d 2,4,6-tri-Cl                                                                          3 "    "           b.p. 202-205° C/1.2 mmHg              (55)  2,4,6-tri-CH.sub.3                                                                    3 "    "           b.p. 160-163° C/0.8 mmHg              (56)  --      0 H    CH.sub.2 COOH                                                                             m.p. 168.5-170°  C                    (57)  "       " "    CH(CH.sub.3)COOH                                                                          m.p. 125-127° C                       (58)  "       " "    CH(CH.sub.3)COOCH.sub.3                                                                   m.p. 48.5-49.5° C                     (59)  4-CH.sub.3                                                                            1 "    CH.sub.2 CH.sub.2 COOH                                                                    m.p. 121-122° C                       (60)  "       " "    CH(CH.sub.3)COOH                                                                          m.p. 139.5-140.5° C                   (61)  "       " "    CH(CH.sub.3)COOCH.sub.3                                                                   m.p. 57-59° C                         (62)  4-Cl    " "    CH.sub.2 CH.sub.2 COOH                                                                    m.p. 157.5-158.5° C                   (63)  "       " "    CH(CH.sub.3)COOH                                                                          m.p. 142.5-144° C                     (64)  "       " "    CH.sub.2 CH.sub.2 CH.sub.2 COOH                                                           m.p. 134.5-136° C                     (65)  "       " "    C(CH.sub.3).sub.2 COOH                                                                    m.p. 169-170.5° C                     (66)  4-CH.sub.3 O                                                                          " "    CH.sub.2 CH.sub.2 COOH                                                                    m.p. 131.5-133.5° C                   (67)  "       " "    CH(CH.sub.3)COOH                                                                          m.p. 139.5-141° C                     (68)  4-CH.sub.3 S                                                                          " "     CH.sub.2 CH.sub.2 COOH                                                                   m.p. 127-129° C                       (69)  4-NO.sub.2                                                                            " "    CH(CH.sub.3)COOH                                                                          m.p. 174.5-175.5° C                   (70)  2,4-di-Cl                                                                             " "    "           m.p. 136.5-137.5° C                   (71)  2-CH.sub.3 -5-Cl                                                                      " "    "           m.p. 150-151° C                       (72)  2,4,6-tri-Cl                                                                          " "    CH.sub.2 CH.sub.2 COOH                                                                    m.p. 164-165° C                       (73)  2,4,6-tri-CH.sub.3                                                                    " "    CH(CH.sub.3)COOH                                                                          m.p. 155.5-157.5° C                   (74)  "       " "    CH(CH.sub.3)COOCH.sub.3                                                                   m.p. 105.5-107° C                     (75)  "       " "    CH.sub.2 CH.sub.2 CH.sub.2 COOOH                                                          m.p. 133-133.5° C                     (76)  --      0 CH.sub.3                                                                           CH.sub.2 COOH                                                                             m.p. 193-184.5° C                     (77)  41      "                                                                                ##STR39##                                                    (78)  4-Cl    1 CH.sub.3                                                                           "           m.p. 180.5-182° C                     (79)  "       " "    CH.sub.2 COOCH.sub.3                                                                      m.p. 80-80.5° C                       (80)  4-CH.sub.3                                                                            " CH.sub.2 COOH                                                                       CH.sub.2 COOH                                                                            m.p. 189.5-190.5° C                   (18)  4-Cl    " "    "           m.p. 226° C                           (82)  --      0 .sbsb.d                                                                            "           m.p. 194-195° C                       (83)  4-CH.sub.3 O                                                                          1 "    "           m.p. 177-178.5° C                     (84)  2,4,6-tri-CH.sub.3                                                                    3 "    "           m.p 169-171° C                        (85)  2,4-di-CH.sub.3                                                                       2 "    "           m.p. 153-155° C                       (86)  4-CH.sub.3                                                                            1 CH.sub.2 COOCH.sub.3                                                               CH.sub.2 COOCH.sub.3                                                                      m.p. 99-100° C                        (87)  "       " CH.sub.3                                                                           CH.sub.2 CH.sub.2 OOC.CH.sub.3                                                            b.p. 179-180° C/1 mmHg                                                 m.p. 55-56° C                         (88)  4-Cl    " "    "           m.p. 70-73° C                         89)   --      0 "    "           m.p. 82-73° C                         (90)  4-CH.sub.3                                                                            1 "                                                                                   ##STR40##  m.p. 85-86.5° C                       (91)  4-Cl    " "    "           m.p. 50-50.5° C                       (92)  --      0 "    "           n.sub. D.sup.22 1.5632                       (93)  4-CH.sub.3 O                                                                          1 H    CH.sub.2 CH.sub.2 COONa                                                                   m.p. 301-304° C                       (94)  "       " "    CH.sub.2 CH.sub.2 COONH.sub.4                                                             m.p. 142.5-145° C                     __________________________________________________________________________

Generally, the compounds used in the present invention can be preparedby using the conventional methods in high yields by:

1. reacting an aromatic sulfonyl halide of the formula (I), ##STR41##with a corresponding amine of the formula (II),

    HNR.sub.1 R.sub.2 (II)

in an organic solvent such as ether, dioxane, benzene, acetonitrile,tetrahydrofuran or chloroform, or a heterogeneous or homogeneous solventsystem comprising said organic solvent and water, at a temperature inthe range from -20° to 80° C in the presence of a condensing agent suchas amine, sodium carbonate or sodium hydroxide;

2. reacting a carboxylic acid of the formula (III), ##STR42## with ausual esterifying agent;

3. reacting a carboxylic acid of the formula (III) with an alkali; or

4. reacting an alcohol of the formula (IV), ##STR43## with a carboxylicacid, carboxylic acid anhydride or a carboxylic acid halide in asuitable solvent under the conventionally known conditions.

Procedures for preparing the compounds according to the presentinvention are illustrated by the following Examples. Unless otherwiseindicated, all parts, percents, ratios and the like are by weight.

EXAMPLE 1 N-2-hydroxyethyl-2,4-dimethylbenzenesulfonamide

To 40 parts of tetrahydrofuran are added 1.5 parts of ethanolamine and2.5 parts of triethylamine. Into this solution, 10 parts oftetrahydrofuran containing 5 parts of 2,4-dimethylbenzenesulfonylchloride is dropped with stirring. After the dropping, the resultantmixture is stirred as it is for 30 minutes. Subsequently, the salt isremoved by filtration, and the filtrate is freed from the solvent toform a solid. This solid is recrystallized from isopropyl ether toobtain 3.6 parts of N-2-hydroxyethyl-2,4-dimethylbenzenesulfonamide,m.p. 70°-72° C.

EXAMPLE 2 N-3-hydroxypropyl-2,4,6-trichlorobenzenesulfonamide

To 40 parts of tetrahydrofuran are added 1.4 parts of 3-amino-1-propanoland 1.8 parts of triethylamine. Into this solution, 10 parts oftetrahydrofuran containing 5 parts of 2,4,6-trichlorobenzenesulfonylchloride is dropped with stirring. After the dropping, the resultantmixture is stirred for 1 hour. After completion of the reaction, thesalt is removed by filtration, and the filtrate is freed from thesolvent. The resulting oily substance is charged with water and thenallowed to stand to form a solid. This solid is recrystallized fromtoluene to obtain 3.8 parts ofN-3-hydroxypropyl-2,4,6-trichlorobenzenesulfonamide, m.p. 104.5°-106.5°C.

EXAMPLE 3 N-methyl-N-2-hydroxyethyl-benzenesulfonamide

To 100 parts of tetrahydrofuran are added with stirring 21.3 parts ofN-methyl-ethanolamine and 28.6 parts of triethylamine. To this solution,100 parts of tetrahydrofuran containing 50 parts of benzenesulfonylchloride is gradually added with stirring while maintaining thetemperature at below 40° C. After completion of the addition, theresulting mixture is stirred as it is for a while, and then heated forabout 1 hour on a water bath at 50° C to terminate the reaction. Then,the salt is removed by filtration, and the filtrate is freed from thetetrahydrofuran to form an oily substance. This oily substance isdissolved in a mixed solvent comprising benzene and a small amount ofchloroform, and the resulting solution is washed with ammonia water,further washed with water, dried over anhydrous magnesium sulfate,treated with charcoal and then freed from the solvent to obtain 55 partsof an oily substance. The thus obtained oily substance can sufficientlybe used as it is, but may, if necessary, be purified by reduced pressuredistillation, b.p. 168°-169°C/0.2 mmHg.

EXAMPLE 4 N-methyl-N-2-hydroxyethyl-p-chlorobenzenesulfonamide

To 20 parts of tetrahydrofuran is added 3.9 parts ofN-methyl-ethanolamine. To this solution, 10 parts of tetrahydrofurancontaining 5 parts of p-chlorobenzenesulfonyl chloride is added withstirring. After completion of the addition, the resultant mixture isstirred as it is for a while, and then heated for about 1 hour on awater bath at 50° C to terminate the reaction. Then, the salt is removedby filtration, and the filtrate is freed from the solvent, whereby anoily substance is obtained. This oily substance is subjected todistillation under reduced pressure to obtain 4.2 parts of a distillate,b.p. 180° C/0.5 mmHg.

EXAMPLE 5 N-benzenesulfonyl-α-alanine

5 Parts of α-alanine and 4.8 parts of sodium hydroxide are dissolved in20 parts of water. The resulting aqueous solution is charged with 5parts of chloroform containing 10 parts of benzenesulfonyl chloride,subjected to heterogeneous phase reaction, and then stirred at roomtemperature for about 6 hours. After the reaction, the aqueous layer isseparated and then acidified with hydrochloric acid to precipitatecrystals. The crystals are collected by filtration and recrystallizedfrom water to obtain 9.6 parts of N-benzenesulfonyl-α-alanine, m.p.125.5°-127° C.

EXAMPLE 6 N-benzenesulfonyl-α-alanine methyl ester

2 Parts of N-benzenesulfonyl-α-alanine is added to adiazomethane-ethereal solution. After the generation of nitrogen hasceased, the reaction liquid is freed from the ether, incorporated with asmall amount of petroleum ether, and then allowed to stand in a dryice-methanol bath to deposit crystals. The crystals are recrystallizedfrom a mixed solvent comprising butanol and petroleum ether to obtain1.5 parts of N-benzenesulfonyl-α-alanine methyl ester, m.p. 48.5°-49.5°C.

EXAMPLE 7 N-2,4,6-trimethylbenzenesulfonyl-α-alanine

4.2 Parts of α-alanine and 4 parts of sodium hydroxide are dissolved in100 parts of water. The resulting aqueous solution is added with 30parts of chloroform containing 10 parts of2,4,6-trimethylbenzenesulfonyl chloride, subjected to heterogeneousphase reaction, and then stirred at room temperature for 3 hours andfurther at 50° C for about 7 hours. After the reaction, the upperaqueous layer is separated and then acidified with hydrochloric acid toprecipitate crystals. The crystals are collected by filtration andrecrystallized from a mixed solvent comprising acetone and water toobtain 6.5 parts of N-2,4,6-trimethylbenzenesulfonyl-α-alanine, m.p.155.5°-157.5° C.

EXAMPLE 8 N-p-methoxybenzenesulfonyl-α-alanine

2.2 Parts of α-alanine and 2.1 parts of sodium hydroxide are dissolvedin 50 parts of water. Into the resulting aqueous solution, 15 parts oftetrahydrofuran containing 5 parts of p-methoxybenzenesulfonyl chlorideis dropped. The resulting mixture is suspending at first, but becomestransparent after about 30 minutes. The mixture is stirred foradditional 1 hour. After completion of the reaction, the reaction liquidis freed from the tetrahydrofuran by use of an evaporator and thenwashed with benzene, and the aqueous layer is acidified withhydrochloric acid and then allowed to stand in ice-water to precipitatecrystals. The crystals are collected by filtration and thenrecrystallized from a mixed solvent comprising acetone and water toobtain 3.2 parts of N-p-methoxybenzenesulfonyl-α-alanine, m.p.139.5°-141° C.

EXAMPLE 9 N-p-chlorobenzenesulfonyl-sarcosine

4.3 Parts of sarcosine and 4.1 parts of sodium hydroxide are dissolvedin 100 parts of water. To the resulting solution, 35 parts of chloroformcontaining 10 parts of p-chlorobenzenesulfonyl chloride is added, andthe resulting mixture is stirred at 60° C for about 2 hours. After thereaction, the aqueous layer is separated and then acidified withhydrochloric acid to precipitate crystals. The crystals are collected byfiltration and recrystallized from a mixed solvent comprising acetoneand water to obtain 4.6 parts of N-p-chlorobenzenesulfonyl-sarcosine,m.p. 180.5°-182° C.

EXAMPLE 10 N-p-chlorobenzenesulfonyl-sarcosine methyl ester

2 Parts of N-p-chlorobenzenesulfonyl-sarcosine is added to adiazomethane-ethereal solution. After the generation of nitrogen hasceased, the precipitated reaction product is collected by filtration toobtain 1.2 parts of N-p-chlorobenzenesulfonyl-sarcosine methyl ester,m.p. 80°-80.5° C.

EXAMPLE 11 N-p-methoxybenzenesulfonyl-iminodiacetic acid

3.3 Parts of iminodiacetic acid and 3.2 parts of sodium hydroxide aredissolved in 50 parts of water. Into the resulting aqueous solution, 20parts of tetrahydrofuran containing 5 parts of p-methoxybenzenesulfonylchloride was dropped. The resulting mixture is suspending at first, butbecomes transparent when stirred at room temperature for about 1.5hours. The mixture is further stirred at 50° C for about 20 minutes toterminate the reaction. After completion of the reaction, the reactionliquid is freed from the tetrahydrofuran and then acidified withhydrochloric acid to precipitate crystals. The crystals are collected byfiltration and then recrystallized from water to obtain 3.8 parts ofN-p-methoxybenzenesulfonyl-iminodiacetic acid, m.p. 177°-178.5° C.

EXAMPLE 12 N-p-toluenesulfonyl-iminodiacetic acid dimethyl ester

2 Parts of N-p-toluenesulfonyl-iminodiacetic acid is added to adiazomethane-ethereal solution. After generation of nitrogen has ceased,the reaction liquid having a yellow color is allowed to stand overnight.Thereafter, the ether is evaporated to form crystals. The crystals arerecrystallized from methanol to obtain 2.1 parts ofN-p-toluenesulfonyl-iminodiacetic acid dimethyl ester, m.p. 99°-100° C.

EXAMPLE 13 N-benzenesulfonyl-N-phenylglycine

7.7 Parts of N-phenylglycine and 5 parts of sodium hydroxide aredissolved in 30 parts of water. Into the resulting solution, 5 parts ofchloroform containing 10 parts of benzenesulfonyl chloride is droppedwith stirring. After the dropping, the resulting mixture is stirred atroom temperature for 4 hours and then at 50° C for 30 minutes.Subsequently, the aqueous layer is separated from the reaction mixtureand then acidified with hydrochloric acid to form an oily substance. Byrubbing on the inner wall of a flask with spatula, crystallized productsare formed. The crystals are recrystallized from a mixed solventcomprising methanol and water to obtain 4.2 parts ofN-benzenesulfonyl-N-phenylglycine, m.p. 166°-167° C.

EXAMPLE 14 N-methyl-N-p-chlorobenzenesulfonyl)-2-aminoethyl acetate

To 20 parts of anhydrous benzene are added 5 parts ofN-methyl-N-2-hydroxyethyl-p-chlorobenzenesulfonamide and 2.2 parts oftriethylamine. Into this solution, 2 parts of acetyl chloride is droppedwith stirring. After completion of the dropping, the resulting mixtureis stirred as it is for a while. Subsequently, the salt is separated byfiltration and washed with tetrahydrofuran. The filtrate is concentratedby means of an evaporator and then freed from the solvent under highvacuum to form a solid. This solid is recrystallized from methanol toobtain 3.7 parts of (N-methyl-N-p-chlorobenzenesulfonyl)-2-aminoethylacetate, m.p. 70°-73° C.

EXAMPLE 15 N-methyl-N-p-chlorobenzenesulfonyl)-2-aminoethyl benzoate

To 30 parts of anhydrous benzene are added 5 parts ofN-methyl-N-2-hydroxyethyl-p-chlorobenzenesulfonamide and 2.3 parts oftriethylamine. Into this solution, 2.5 parts of benzoyl chloride isdropped. The resulting mixture is stirred for a while and then heated at50° C for about 1 hour. After completion of the reaction, the salt isseparated by filtration and washed with tetrahydrofuran. Subsequently,the filtrate is freed from the solvent to form an oily substance. Thisoily substance is allowed to stand in high vacuum and then charged withwater to form a solid. The solid is recrystallized from ethanol toobtain 5.2 parts of (N-methyl-N-p-chlorobenzenesulfonyl)-2-aminoethylbenzoate, m.p. 50°-50.5° C.

The benzenesulfonamide derivatives according to the present inventionhave prominent plant growth-regulating actions, and particularly havestrong effects of controlling the elongation of heights and nodes ofplants. In actual application, they may be sprayed as they are or may beused after formulating them into any of granules, dusts, emulsifiableconcentrates, wettable powders and aqueous preparations.

The amount of the benzenesulfonamide derivative used varies depending onthe manner of application, but when desired to be applied to soil, thebenzenesulfonamide derivative is used at a concentration in the rangefrom 0.5 to 500 p.p.m., preferably from 10 to 100 p.p.m., per part ofsoil, while when desired to be applied to stems and leaves by spraying,it is to use an emulsifiable concentrate or aqueous preparationcontaining as an active ingredient at least one benzenesulfonamidederivative at a concentration in the range from 100 to 10,000 p.p.m.,preferably from 500 to 5,000 p.p.m., so that the chemical adheres to thewhole stems and leaves but does not fall down as droplets. If the amountof the benzenesulfonamide derivative used is smaller than said range,the plant growth-regulating effect of the chemical is not sufficient,while if the amount thereof is larger than said range, plants areundesirably injured in growth.

Each of the preparations according to the present invention is desirablyused properly according to the kind and size of cultivated plants to betreated and the purpose of application.

The granule according to to the present invention is obtained by mixingthe compound of the present invention as active ingredient with one ormore of talc, bentonite, clay, kaolin, diatomaceous earth, vermiculiteand the like extender for agricultural use, adding a fixing agent orwater to the resulting mixture, sufficiently pulverizing the mixture,and then granulating the pulverized mixture.

The aqueous preparation is obtained by dissolving the present compoundas active ingredient in water.

The wettable powder is obtained by adding the present compound as activeingredient and a dispersant to the aforesaid extender as carrier, andthen sufficiently pulverizing the resulting mixture.

The dust is obtained by adding the present compound as active ingredientto the aforesaid extender as carrier, and then sufficiently pulverizingthe resulting mixture.

The emulsifiable concentrate is obtained by adding the present compoundas active ingredient to an organic solvent such as benzene, xylene,dioxane, acetone, cyclohexane, isophorone or alcohol, adding to theresulting mixture any of such emulsifiers as alkylsulfuric acid esters,alkylsulfonic acid salts, arylsulfonic acid salts, polyethylene glycolethers, polyethylene glycol esters and polyhydric alcohol ester, andthen sufficiently kneading the resulting mixture.

In actual application, the plant growth regulators of the presentinvention may not only be used in combination with vehicles and othersurfactants used in agriculture to expect the enhancement and accuracyof the effects thereof, but may also be used in admixture with otheragricultural chemicals such as fungicides, insecticides, nematocides andherbicides, and with fertilizers.

The present invention is illustrated in detail below with reference toexamples, but it is needless to say that the invention is not limited tothe examples, including the kinds of the compounds and additives usedand the mixing proportions, but is variable within a wide scope. In theexamples, the names of the compounds are represented by the exemplifiednumbers of the compounds.

EXAMPLE 16

500 Grams of a synthetic soil comprising sea sand, mountain soil andpeat was packed in each of 12 cm unglazed pots. In each pot werecultivated three Pot-mum plants (variety: Snow Ridge). Two weeks afterplanting, the plants were pinched, and, 2 weeks after pinching when newbuds had elongated, each of the present compounds at such concentrationsas shown in Table 2 was applied to the plants. On the 42nd day after thechemical treatment, the plants were observed to investigate the plantgrowth-regulating effects of the present compounds. The results obtainedwere as set forth in Table 2.

The evaluation of the effects was carried out in such a manner that aheight elongation of the plant was calculated from the differencebetween the initial height of the Pot-mum at the time of chemicaltreatment and the height thereof on the 42nd day after the chemicaltreatment, and was represented by a height index calculated by assumingas 100 the height of the plant of non-treated area. The value is anaverage value of three Pot-mum plants.

                                      Table 2                                     __________________________________________________________________________    Pot-mum test                                                                        Spray   Soil         Spray   Soil                                       Compound                                                                            treatment                                                                             treatment                                                                           Compound                                                                             treatment                                                                             treatment                                  No.   (4000 ppm)*                                                                           (100 ppm)                                                                           No.    (4000 ppm)*                                                                           (100 ppm)                                  __________________________________________________________________________    (1)   92      79    (17)   78      72                                         (2)   93      72    (18)   95      79                                         (3)   90      72    (19)   84      85                                         (4)   95      87    (20)   89      86                                         (5)   84      87    (21)   78      77                                         (6)   74      71    (23)   77      60                                         (8)   92      90    (26)   77      61                                         (9)   85      78    (27)   79      63                                         (10)  78      86    (28)   80      79                                         (11)  82      87    (29)   77      79                                         (12)  80      70    (30)   61      59                                         (14)  95      86    (32)   92      89                                         (15)  92      91    (33)   90      85                                         (34)  91      93    (50)   90      85                                         (35)  86      88    (51)   85      72                                         (36)  82      75    (52)   86      84                                         (37)  93      78    (53)   91      83                                         (38)  95      90    (54)   89      78                                         (39)  66      76    (55)   88      80                                         (40)  79      66    (56)   98      86                                         (41)  95      74    (57)   98      64                                         (42)  91      73    (58)   81      75                                         (43)  92      83    (59)   66      46                                         (44)  92      80    (60)   80      67                                         (45)  87      78    (61)   90      75                                         (46)  91      86    (62)   74      76                                         (47)  89      84    (63)   76      54                                         (48)  94      77    (64)   75      79                                         (49)  92      87    (66)   78      67                                         (67)  88      72    (79)   94      67                                         (68)  89      88    (80)   83      75                                         (69)  85      86    (81)   76      85                                         (70)  81      69    (83)   88      84                                         (71)  58      54    (84)   96      85                                         (72)  90      88    (85)   91      82                                         (73)  69      67    (86)   94      86                                         (74)  78      78    (87)   95      90                                         (75)  93      67    N-dimethyl-                                                                   amino-                                                    (76)  93      72    succinamic                                                                           80      101                                                            acid                                                      (77)  90      85    Non-   100     100                                                            treatment                                                 __________________________________________________________________________

EXAMPLE 17

500 Grams of paddy soil was packed in each of plastic-made Neubauerpots. To the soil of each pot were added 25 mg. (50 p.p.m. per part ofthe soil) of each of the present compounds shown in Table 3 and properamounts of fertilizer and water. Thereafter, 25 seeds of barley(variety: Yunagi) were sowed to investigate the influence of thechemical on the initial growth of the barley. The results obtained wereas set forth in Table 3.

                  Table 3                                                         ______________________________________                                        Neubauer pot test                                                                              Fresh                   Fresh                                Compound Height  weight  Compound Height weight                               No.      (Index) (Index) No.      (Index)                                                                              (Index)                              ______________________________________                                        (3)      91      98      (24)     54     69                                   (6)      89      90      (25)     54     67                                   (7)      90      91      (27)     85     97                                   (9)      89      88      (30)     63     70                                   (11)     93      97      (31)     89     98                                   (13)     89      94      (35)     89     90                                   (14)     85      80      (42)     76     78                                   (16)     86      93      (43)     88     86                                   (17)     85      89      (45)     52     57                                   (20)     76      78      (46)     86     87                                   (21)     90      92      (47)     67     70                                   (22)     51      61      (48)     66     66                                   (23)     76      88      (49)     69     75                                   (51)     68      66      (70)     90     92                                   (52)     82      89      (72)     81     85                                   (54)     77      71      (73)     91     87                                   (56)     67      73      (75)     91     107                                  (57)     67      73      (76)     61     68                                   (58)     66      82      (77)     79     81                                   (59)     90      90      (78)     57     63                                   (61)     91      98      879)     66     77                                   (62)     82      78      (82)     86     95                                   (63)     69      82      (83)     78     91                                   (64)     82      81      (84)     89     103                                  (65)     81      82      (85)     90     93                                   (66)     70      76      (86)     80     88                                   (67)     88      98      (88)     72     86                                   (68)     74      86      (89)     91     98                                   (69)     70      69      (90)     59     77                                   (91)     75      102                                                          (92)     61      85                                                           (93)     71      76                                                           (94)     72      78                                                           Non-                                                                          treatment                                                                              100     100                                                          ______________________________________                                    

EXAMPLE 18

Pot tests were carried out by using wheat plants aiming at a preventionof lodging owing to an elongation control between nodes of rice plantsand wheat plants and also aiming at an increased yield owing to anincrease in number of tillers and ears.

3 Kilograms of paddy soil was packed in each of Wagner pot having areaof 1/5000 a, a moisture of the soil was adjusted to a field condition,0.5 g each of N, P₂ O₅ and K₂ O was applied to all layers of the soil,and then 10 seeds of wheat (variety: Ushio) were sowed on December 7.The cultivation was carried out after adjusting to 3 plants per pot bythinning on January 23. The plants were treated with a definiteconcentration of the present compounds on March 1 and April 1 toinvestigate their growth thereafter.

The investigated results are shown in Table 4 below.

                                      Table 4                                     __________________________________________________________________________                                                      Yield                                                     Plant     Number    Weight                                                                             Weight of                                            length    of stem   of   unhulled               Compound                                                                             Date of Treatment                                                                      Treatment                                                                          Concentration                                                                          4/18 5/28 4/18 5/28 straw                                                                              wheat                  __________________________________________________________________________    (28)   3/1      Spray                                                                              4000 ppm*                                                                              94   97   85   104  102  110                    (30)   "        "    "        96   85   98   115   98  108                    (28)   "        Soil 100 mg/pot                                                                             97   96   114  126  105  120                    (30)   "        "    "        82   69   113  145   99  115                    (28)   4/1      Spray                                                                              4000 ppm *                                                                             90   98   86   101  101  108                    (30)   "        "    "        86   97   102  110   91  107                    (28)   "        Soil 100 mg/pot                                                                             100  99   95   103  101  104                    (30)   "        "    "        96   76   89   108   98  105                    Non-                          100  100  100  100  100  100                    treatment                                                                            --       --   --       (73 cm)                                                                            (82.2 cm)                                                                          (29.3)                                                                             (24.3)                                                                             (47.1g)                                                                            (46.5g)                __________________________________________________________________________     *Concentration of active ingredient                                      

What is claimed is:
 1. A method for regulating the elongation of plantsso as to increase their resistance to lodging, characterized by applyinga plant growth regulator containing as active ingredient abenzenesulfonamide derivative represented by the general formula,##STR44## wherein X is a halogen atom, alkyl group having 1 to 5 carbonatoms, nitro group, amino group, alkoxy group having 1 to 5 carbonatoms, alkylthio group having 1 to 5 carbon atoms, alkylsulfonyl grouphaving 1 to 5 carbon atoms, or a group of the formula R₃ CONH-- (whereR₃ is alkyl group having 1 to 5 carbon atoms); n is an integer of 0 to5; R₁ is hydrogen or alkyl group having 1 to 5 carbon atoms, and R₂ ishydroxyalkyl group having 1 to 5 carbon atoms.
 2. A method according toclaim 1, wherein said benzenesulfonamide derivative is applied to soilat a concentration of 0.5 to 500 ppm per part by weight of soil.
 3. Amethod according to claim 2, wherein said concentration is 10 to 100 ppmper part of soil.
 4. A method according to claim 1, wherein saidbenzenesulfonamide derivative is applied to stems and leaves of plantsby spraying with an aqueous preparation or an emulsifiable concentratecontaining said compound in a concentration of 100 to 10,000 ppm.
 5. Amethod according to claim 4, wherein said aqueous preparation oremulsifiable concentrate contains said active ingredient at aconcentration of 500 to 5,000 ppm.
 6. A method according to claim 1,wherein said benzenesulfonamide derivative is a compound of the formula,##STR45## wherein R is hydrogen, methyl or ethyl.
 7. A method accordingto claim 1, wherein said benzenesulfonamide derivative is a compound ofthe formula, ##STR46## wherein X is methyl or a halogen atom.
 8. Amethod according to claim 1, wherein said benzenesulfonamide derivativeis a compound of the formula, ##STR47## wherein X is methoxy, chlorineor fluorine atom.
 9. A method according to claim 1, wherein saidbenzenesulfonamide derivative is a compound of the formula, ##STR48##wherein R is --CH₂ --CH₂ OH, --CH₂ --CH₂ --CH₂ OH, --CH₂ --CH₂ --CH₂--CH₂ --OH or --C(CH₃)₂ --CH₂ --OH.
 10. A method according to claim 1,wherein said benzenesulfonamide derivative is a compound of the formula,##STR49## wherein R is hydrogen or methyl.
 11. A method according toclaim 1, wherein said benzenesulfonamide derivative is a compound of theformula, ##STR50##
 12. A method according to claim 1, wherein saidbenzenesulfonamide derivative is a compound of the formula, ##STR51##13. A method according to claim 1, wherein said benzenesulfonamidederivative is a compound of the formula, ##STR52##
 14. A methodaccording to claim 1, wherein said benzenesulfonamide derivative is acompound of the formula, ##STR53##
 15. A method according to claim 1,wherein said benzenesulfonamide derivative is a compound of the formula,##STR54##
 16. A method according to claim 1, wherein saidbenzenesulfonamide derivative is a compound of the formula, ##STR55##17. A method according to claim 1, wherein X is a halogen atom, methylor methoxy; n is an integer of 0 to 3; R₁ is hydrogen, methyl or ethyl;R₂ is --CH₂ --CH₂ --OH, --CH₂ --CH₂ --CH₂ --OH, or hydroxybutyl when R₁is hydrogen; and R₂ is hydroxyethyl when R₁ is methyl or ethyl.
 18. Amethod according to claim 1, wherein said benzenesulfonamide derivativeis a compound of the formula, ##STR56##